Investigation of incidence and geographic distribution of gliomas in Canada from 1992 to 2010: a national population-based study highlighting the importance of exposure to airport operations.

Background: Gliomas account for over two-thirds of all malignant brain tumors and have few established risk factors beyond family history and exposure to ionizing radiation. Importantly, recent studies highlighted the exposure to ultrafine particles (UFP) as a putative risk factor for malignant brain tumors. Methods: Clinical and geographic data encompassing all provinces and territories from 1992 to 2010 was obtained from the Canadian Cancer Registry and Le Registre Québécois du Cancer. Linear regression and joinpoint analyses were performed to assess incidence trends. Significantly higher and lower incidence postal codes were then interrogated using Standard Industrial Classification codes to detect significant industrial activity. Results: In Canada, between 1992 and 2010, there were ~32,360 cases of glioma. Of these, 17,115 (52.9%) were glioblastoma. The overall crude incidence rates of 5.45 and 2.87 cases per 100,000 individuals per year for gliomas and glioblastomas, respectively, were identified. Our findings further revealed increasing crude incidence of gliomas/glioblastomas over time. A male predominance was observed. Provinces leading in glioma incidence included Quebec, Nova Scotia, and New Brunswick. Significantly lower crude incidence of glioma was found in Nunavut, Northwest Territories, Ontario, and Alberta. A putative regional clustering of gliomas was observed, with higher incidence rates in postal code areas correlating with industrial activity related to airport operations. Conclusion: This study describes the geographic distribution of the glioma disease burden and, potentially, identifies industrial activity related to airport operations as potentially being associated with higher incidence of this cancer.

Population-Based Study Detailing Cutaneous Melanoma Incidence and Mortality Trends in Canada.

Background: Cutaneous melanoma (CM) is one of the most fatal types of skin cancer. Alarmingly, increases in incidence and mortality were noted globally for this malignancy, despite increase in understanding of melanoma pathogenesis and enhanced prevention efforts. Methods: Data was extracted for CM patients for provinces and territories (except Quebec) using two independent, population-based registries. Analysis was performed using both clinical and pathological characteristics: tumor morphologic classification, age, sex, anatomic site affected and place of residence. Mortality trends were assessed over a 7-year period. Results were compared to prior findings for 1992-2010. Results: During 2011-2017 39,610 patients were diagnosed with CM, with 5,890 reported deaths. National crude CM incidence was 20.75 (age-standardized incidence: 14.12) cases per 100,000 individuals per year. Females accounted for 45.8% of cases and 37.1% of deaths. While CM incidence rates continue to increase in both sexes, since 2013 the CM mortality is declining. We observed important differences across the provinces/territories, where Nova Scotia, Prince Edward Island, southern Ontario/British Columbia and certain coastal communities of New Brunswick demonstrated higher CM incidence and mortality rates. The observed incidence and mortality trends for 2011-2017 validate and extend earlier observations from 1992 to 2010 for CM. Conclusion: This population-based study highlights that while melanoma's incidence is increasing in Canada, mortality rates are for the first time decreasing since 2013. We detail regional distribution of this cancer highlighting communities in southern/coastal areas, as being most at risk as well as the latest trends of melanoma incidence by age, sex and anatomic site. In males, melanoma is more common on the head/trunk, while in females on the extremities. Notably, Acral Lentiginous Melanoma was the only CM subtype that was more common in females, which primarily affects hands and feet.

Epidemiologic trends and geographic distribution of patients with gallbladder and extrahepatic biliary tract cancers in Canada.

BACKGROUND: Gallbladder and biliary tract cancers are rare malignancies that carry a poor prognosis. Research on their epidemiologic trends is scarce. METHODS: We performed a retrospective analysis of the data in Canada using population-based cancer registries from 1992 to 2010. The incidence and mortality of gallbladder and extrahepatic bile duct cancers were examined at the levels of provinces/territories, cities, and Forward Sortation Area (FSA) postal codes. RESULTS: The incidence and mortality rates decreased over the study period. The average national incidence rate of gallbladder and biliary tract cancers was 30.92 cases per million individuals per year. Higher than average incidence rates were observed in Manitoba, Saskatchewan and Québec; there were contiguous regions with high incidence in Saskatchewan and Manitoba that suggest an area of putative case clustering. Higher incidence of gallbladder cancer was observed in women, whereas higher incidence of extrahepatic bile duct cancers was noted in men. Lower socioeconomic status and Hispanic race were found to be risk factors for gallbladder and biliary tract cancers. CONCLUSION: This is the first study to analyze the burden of gallbladder and biliary tract cancers in Canada. The geographic clustering trends present new avenues for research on environmental triggers.

Non-Melanoma Skin Cancer Distribution in the Russian Federation.

BACKGROUND: Non-melanoma skin cancer (NMSC) incidence has been increasing steadily around the world. The aim of the study is to describe geographic trends in incidence and mortality of NMSC in Russia between 2007 and 2017 and compare findings to other European countries. METHODS: We used geospatial analysis to map the incident cases and descriptive statistical analysis to analyze trends. Additionally, we assessed the relationship between ethnicity, geographic latitude/longitude, and NMSC incidence/mortality rates. We retrospectively analyzed the data from the Moscow Oncology Research Institute, Ministry of Health of the Russian Federation, for 2007-2017. Routine methods of descriptive epidemiology were used to study incidence and mortality rates by age groups, years, and jurisdictions (i.e., Federal Districts and Federal Subjects). RESULTS: In total, 733,723 patients were diagnosed with NMSC in Russia over the period 2007-2017, of whom 63% were women. The overall age-standardized incidence and mortality rates were 29.64/100,000 and 0.70/100,000, respectively. There was a consistent increase in age-standardized incidence rates over the study period, with a decreasing mortality rate. Geographic mapping revealed north-to-south and east-to-west gradients for NMSC. CONCLUSIONS: This study demonstrated longitudinal trends for NMSC incidence in Russia documenting that skin phototype, latitude/longitude, climate zones, and cultural practices remain dominant risk factors defining the epidemiology of NMSC. Moreover, this work identified several regions in the country (i.e., Republic of Adygea, Samara, Krasnodar Krai, etc.), where patient education/sun awareness campaigns will be useful to help reduce the risk of this malignancy.

Geographic Variations in Cutaneous Melanoma Distribution in the Russian Federation.

BACKGROUND: Cutaneous melanoma (CM) incidence has been increasing around the world. The goal of this study is to describe geographic trends in incidence and mortality of CM in Russia between 2001 and 2017. METHODS: To achieve this we used geo-informatic technique (mapping) and descriptive statistical analysis. Additionally, we studied the associations between ethnicity, geographic latitude/longitude, and CM incidence/mortality rates. We retrospectively analyzed the data from the Moscow Oncology Research Institute, Ministry of Health of the Russian Federation, for the period of the study. Routine methods of descriptive epidemiology were used to study incidence and mortality rates by age groups, years, and jurisdictions (i.e., Federal Districts and Federal Subjects of Russia). RESULTS: In total, 141,597 patients were diagnosed with melanoma in Russia over the period 2001-2017, of whom 62% were women. The overall age-standardized incidence and mortality rates were 4.27/100,000 and 1.62/100,000, respectively. Geographic mapping revealed north-to-south and east-to-west gradients. As the study was fully descriptive, retrospective, and based on official statistical reports, detailed characteristics of clinical forms, anatomic sites, Breslow depth, and treatments could not be analyzed. CONCLUSIONS: This study outlined the burden of melanoma in the Russian Federation, and the trends were similar to those observed in countries with similar latitudes and skin phenotype. The importance of the skin color gradient and recreational/cultural practices were some of the most important risk factors highlighted in this study for the development of melanoma in Russia.

Analysis of incidence, mortality trends, and geographic distribution of breast cancer patients in Canada.

BACKGROUND/PURPOSE: Breast cancer is the malignancy with the highest incidence rate excluding non-melanoma skin cancers, and the second leading cause of cancer-related deaths among Canadian women. Many modifiable risk factors have been linked to the pathogenesis of this disease. The purpose of this study is to analyze the epidemiology of breast cancer in Canada and to examine its geographic distribution to help identify new risk factors for this disease. METHODS: Three independent population-based cancer registries were used to retrospectively analyze demographic data from Canadian women diagnosed with invasive breast cancer across all provinces and territories between 1992 and 2010. The incidence and mortality rates were assessed at the provincial, city, and forward sortation area (FSA) postal code levels. RESULTS: The overall age-adjusted incidence rate was 114.4 cases per 100,000 females per year. Six provinces and several groups of FSAs had significantly higher incidence rates. There was a significant increase in incidence and decrease in mortality rates between 1992 and 2010. The overall mortality rate was 31.5 deaths per 100,000 females per year. However, three provinces had significantly higher mortality rates. CONCLUSION: By identifying high-incidence areas for breast cancer, our study will help identify patient populations that are at higher risk for this malignancy. It will also act as a foundation for future studies to establish novel risk factors for this disease.

Identification of significant geographic clustering of polycythemia vera cases in Montreal, Canada.

BACKGROUND: Polycythemia vera (PV) is a chronic myeloproliferative neoplasm associated at times with debilitating symptoms and a significant mortality rate. Understanding the demographics, epidemiology, and geography of this disease may provide further insight into important risk factors associated with its development. The objective of this study was to analyze patient demographics, incidence, and mortality rates, as well as the geographic distribution of PV patients in Canada between 1992 and 2010. METHODS: This study was achieved by analyzing the Canadian Cancer Registry, Le Registre Québécois du Cancer, and the Canadian Vital Statistics patient databases. RESULTS: A total of 4645 patients were diagnosed with PV between 1992 and 2010. While the annual incidence rate of this cancer fluctuated in Canada, mortality rate analysis indicated a decreasing trend. Geographically, PV incidence rates were notably elevated in the province of Quebec compared with the Canadian average. Further analysis of high-incidence forward sortation areas indicated a striking clustering of cases in the H4W region encompassing the Côte-Saint-Luc borough of Montreal, with an incidence of 102.97 (95% confidence interval, 75.11-137.79) cases per million per year, which is >13 times the national average. CONCLUSION: The residential area of Côte-Saint-Luc is an important PV cluster in Canada, with high concentration of retirement homes and geriatric hospices. Also, Jewish residents comprise >60% of the population in this neighborhood. These findings suggest that an older age and, potentially, an inherent genetic predisposition may be implicated in the pathogenesis of this malignancy. This study provides a comprehensive overview of PV burden/geographic distribution of cases in Canada.

Multiple myeloma epidemiology and patient geographic distribution in Canada: A population study.

BACKGROUND: Multiple myeloma (MM) is a malignancy of mature plasma cells. Environmental risk factors identified for this malignancy, among others, include farming and exposure to pesticides. METHODS: Using 3 independent population-based databases (the Canadian Cancer Registry, le Registre Québécois du Cancer, and Canadian Vital Statistics), this study analyzed patients' clinical characteristics and the incidence, mortality, and geographic distribution of MM cases in Canada during 1992-2015. RESULTS: In total, ~32,065 patients were identified, and 53.7% were male. The mean age at the time of diagnosis was 70 ± 12.1 years. The average incidence rate in Canada was 54.29 cases per million individuals per year, and linear regression modeling showed a steady rise in the annual rate of 0.96 cases per million individuals per year. At the provincial level, Quebec and Ontario had significantly higher incidence rates than the rest of Canada. An analysis of individual municipalities and postal codes showed lower incidence rates in large metropolitan areas and in high-latitude regions of the country, whereas high incidence rates were observed in smaller municipalities and rural areas. Land use analysis demonstrated increased density of crop farms and agricultural industries in high-incidence areas. A comparison with the available data from 2011-2015 showed several consistent trends at provincial, municipal, and regional levels. CONCLUSIONS: These results provide a comprehensive analysis of the MM burden in Canada. Large metropolitan cities as well as high-latitude regions were associated with lower MM incidence. Higher incidence rates were noted in smaller cities and rural areas and were associated with increased density of agricultural facilities.

Analysis of acute myeloid leukemia incidence and geographic distribution in Canada from 1992 to 2010 reveals disease clusters in Sarnia and other industrial US border cities in Ontario.

BACKGROUND: Several risk factors have been implicated in acute myeloid leukemia (AML) leukemogenesis. However, the epidemiologic distribution and precise triggers for AML in Canada remain poorly understood. METHODS: In this study, demographic data for AML patients in Canada from 1992 to 2010 were analyzed using 3 independent population-based cancer registries. The AML incidence and mortality rates were examined at the levels of province/territory, city, and forward sortation area (FSA) postal code. RESULTS: In total, 18,085 patients were identified. AML incidence was documented to be 30.61 cases per million individuals per year (95% confidence interval [CI], 30.17-31.06) from 1992 to 2010. Five industrial cities in Ontario were identified where incidence rates were significantly higher than the national average: Sarnia, Sault Ste. Marie, Thunder Bay, St. Catharines, and Hamilton. Analysis at the FSA postal code level identified significant patient clusters of AML in these cities. Specifically, FSA N7V in Sarnia, Ontario had an incidence of 106.81 (95% CI, 70.96-161.86) cases per million individuals per year, which is >3 times higher than the national average. The pollution from local oil refineries and chemical plants in Sarnia may be implicated as a risk factor for AML in that city. Analysis of mortality rates at the province and city levels corroborated the findings from the incidence data. CONCLUSION: These results provide a comprehensive analysis of AML burden in Canada and reveal striking geographic case clustering in industrial Ontario cities and potentially implicate exposure to materials/pollution from these plants as an important risk factor for developing AML in Canada.